Process for welding two metals of unequal fusibility.



0. KOHLER. PROCESS FOR WELDING TWO METALS 0F UNEQUAL FUSIBILITY.

APPLICATION FILED DC.28, 1911.

Patented Mar. 11,1919.

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- UNITED STATES PATENT QFFICE.

Q 7 conimn KOI-ILER, or zuzarcn, SWITZERLAND.

' rnoonss roa WELDING TWO METALS or UNEQU'AL FUSIBILITY. 7

' To dZZ wkom it may concern: 7

Be it known that I, CONRAD KoHLER', a citizen of the Republic, of Switzerland, 1e siding at Hardturmstrasse 19, Zurich 5, Switzerland, have invented certain new and useful Improvements in Processes for \VeldingTwo Metals ofUnequal .Fusibility and I do hereby'declare the following to bea clear, full, and exact description of the invention, such as will enable others skilled in the art'to which it. appertains to make and use the same, reference being had to the accompanying drawing, and to letters or figures of reference marked thereon, which form a part/of th s specification.

This invention relates to aprocess for welding two'metals'of unequal frisibility' by means of a previous welding'on of a thin layer of an auxiliarymetal to themetal which hasthe lesser fusibility. According to the novel process, said auxiliary metal layer is Welded on to the metalof lesser fusibility by means of a reducing flame (autogenous 1 which a layer of copper has beeniwelded by the autogenous welding process', and which is thus prepared' for the'welding' on of a: f fairly large quantity of copper. Figs. 2 and 3 showhow'the' same iron bar embedded in a mold, for the casting-ion of a copper bar. 7 Fig. 4 shows how an iron rod prepared by process) 1 For the auxiliary metal layer that has to bewelded on to the metal of lesser fusibility by means of the reducing flame, the same metal as the second metal tobe connected can also :be'employed; The process. can especially be employed for the Welding: of

and; then welding copper to the said layerand.

In such a case,'ithe auxiliary. layer cancon sist of copper. Tlnsprocess can be especially advantageously employed when it is desired to'connect iron and 'copper'with one another in such a manner that the electric current led through" such a combined or 'joined piece, meets with the least possible resistance atthe point of connection. A

According to a process hitherto known for the connection of two metals of unequal fusi-j bility, it has already been "proposed to weld a thin auxiliary layer to-the metal of lesser i fusibility. It was, however, merely prescribed that this had to be doneby means of a bl'ow-pipe,'but without specially prescribing the working of this blow-pipe or of its flame. :If an air blow-pipe, (forin'st'ance an oxyhydrogen blow-pipe) be employed,

an ample quantity of air, 71. e. anoxidizmg medium, will beled to the weld. Thus a layer of oxid (slag) is formed, which ren- Specification of Letters Patent. 7 P t nt d Mar. 11, 1919. Applicationfiled December 28, 19 17. Serial m. 209,307.

ders impossible a reliable and uniform coir' ent invention solves the problem of Welding together as closely as possible, two metals of unequal fusibility. In the autogenous welding process, where either oxygen and hydrogen, or oxygen and acetylene, are employed in the welding burner,a reducing flame is produced, '5. 6.

either hydrogenor acetylene is presentin excessive quantities. Every fformation'of slag is avoided. The melted auxiliary metal is'just as pure as the topmost layer of the metaljwith the lesser fusibility, and the lat terfafterthe first welding step, is providdf with a completely' pure'coating, which can'j be then'e'asily and'eleanly joined'to thesecond metal to be welded, i

The drawing-"shows two -eXamples,Figure 1 illustrating an lronbar on the top end of the autogenous'welding process'and a copper rod are embedded in'amo1d,so that they can "be'welded together by means of liquidi 9O fthrougl the apparatuses shown in Figs. '21 s copper. Figs. 3 and 5 are cross-sections referring" to'the drawing, 1 denotes in paratus, a suitable quantity of copper havping been melted oil a thin copper rod by,

means'of "a reducingflame. This isdone i when the upper part of the iron barhas been 7 made red hot by means of the .oXy-acetylene r flame. After cooling, the upper end of the, f

piece 1,2, whichhas been thus joined, is

cleanly rounded oil, either by machining or filing, especiallyat its top end'surface, and

the bar is then placed in a mold as shown in Fig. 2. 3 is the box which is nearlyfilled,

with molding sand. The bar 1 is'rammed;

in, pointing upward in an oblique direction,

so that the smoothly planed end surface of the copper layer 2 is at the top. In the continuation of the joined bar 1, 2, a hollow 5L 7 is made in the sand, corresponding in shape to that of the copper bar that has to be cast on. Fig. 3 shows an 1 imaginary section through the mold .on,the line ,A:B,.C. of Fig. 2. Liquidcopper is now poured in at the funnel 6 until it not only fills up the hollows z-in-the sandfo'rm 4,- 'but overflows at the funnel 7 fora sufiiciently long .timefor one to safely assume that the surface of the auxiliary layer 2 has. melted. This gnaran tees that the .cop-perlayer 2 closely unites with the liquid-copper poured in through the funnel 6. After the casting has takenplace, the moldcanbe taken out of the box 3,.and the combined bar freed from sand; It is now ready for further machining.

. Fig. et shows a longitudinal section through a,mold,.in which a copper bar 13 has. to be.welded .on to an iron bar 11,

which is prepared in a similanway to the ironbarl shown in Fig. 1. At the one end v ofthe. iron bar, a copper plate 12 Zisfirstf welded onjby the. autogenous welding :process, ,The,combinedrban 11, 12 lies in the Copies of thji sljii'atent be obtained for jfiy'e cents each, by addressingthefFGoininissioner Patents; 7 a 7 7 same straight line with the copper bar 13, but there is a small clearance s between the.

'two, iwhich clearance 8 is filled up withthe liquid copper which. is now poured'in. Fig.

5 is. an imaginary sectionrthrough-the mold on the line D-E'ofFigA. Liquidcopperisvnow :poured in at thefunnel 14 until itlfreely ;overfl0ws. at 15.;and 16,1 and one: r can safely assume. that ,both the, auxiliary layer.12r:atfits.,free end,iand also the copper bar. 13 atitsinnerend, havelmelted and the. meltedfparts.closelyjunited with one another Themetal is then allowed to cool, 3 after. whichthecasting can be takemout of the mold. and machined."

What I claim. now as; .my invent on is 1. 'Alprocess for ;welding two metals of unequal fusibility,.which comprises welding.

a layer ofthemetal of easierfusibility to the metaljof less fusibility by av reducin .;flamethereby simultaneously eflecting the eating.

of. .the metals to their. uniting temperature unequal fusibility, consisting in'first welding an auxiliary layer of metalto the metal of lesser fusibility-by a reducing flame, embedding,saidjoinedmetal piece in a mold, providing in the mold ahollow reaching to said metal piece, pouring the second metal in a liquid state into said hollowfand taking the cooled. casting ,out' of the mold.

3. A process for welding two metals of unequal fusibility, consisting first welding, an auxiliary layer of metalto themetal of lesser fusibility by areducing flame cleanly rounding off the auxiliary metal layer j oined; to the first metal, embeddingthe joined metal piece in a mold, providingrin the mold a hollowreaching'to said metal piece, pouringthesecond. metal in a liquid state-into said;

hollow and taking. the cooled casting .out 7 V of the mold. V I

l. A process for weldingtwo metals of un-.

an auxiliary layer 'of ..metal to. one end of equal fusibility, consisting in first welding.

the 'metal-piece of lesser fusibility by a reducing flame,,cleanly roundingoifthe freeend surface of the auxiliary layerof metal,.

embedding the joined metal-piece-in at'box filled withmolding sand, providing a hollow,

in .the sand, the hollowlayingin the contin-- uation of the joined metal -.piece,.pouring,the second metal to be welded in a liquid state into said hollowandiletting it overflowiuntilj the surfaceof the. auxiliary layer of metal is l F melted and taking the cooled castingzout of I V 5. A process for. weldingcopper: to. iron,- consisting in applyin lcoppertothe top end. ofa hot ironbar-witfi theafi of a reducing flame, cleanly. rounding off. the uppenend of the j oined. bar,'-placijng the'metal .barin. a 6

box filled with, sand,1providing a hollow in i the. sand reaching to the smoothly rounded end surface. of the joined bar, pouring liquid. copperiutoi said hollo'w and lettingit over,- flow until the surface .ofthe auxiliary layer has been melted and taking the cooled casting .out; of the box.

. In testimony that. Iclaim'the foregoing my invention, I have signed my. names,

, f Connem ra V Washington,D.. C. 

